Question
Sat July 28, 2012 By:
 

What is the cardinality of set P[P{P(?)}] ??

Expert Reply
Sat July 28, 2012
For any finite set A,
|P(A)| = 2^|A|

We have:
|P(P(P({})))|
= 2^|P(P({}))|
= 2^(2^|P({})|)
= 2^(2^(2^0)))
= 2^2 = 4
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